通过设计具有不对称脊的光栅来降低金属-电介质光栅中的电场增强。

Reducing electric-field-enhancement in metal-dielectric grating by designing grating with asymmetric ridge.

作者信息

Chen Junming, Huang Haopeng, Zhang Yibing, Wang Yonglu, Kong Fanyu, Wang Yanzhi, Jin Yunxia, Chen Peng, Xu Jiao, Shao Jianda

机构信息

Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.

University of Chinese Academy of Sciences, Beijing, 100039, China.

出版信息

Sci Rep. 2018 Mar 27;8(1):5228. doi: 10.1038/s41598-018-22479-3.

DOI:10.1038/s41598-018-22479-3

PMID:29588450

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5869717/

Abstract

Diffraction gratings are an essential optical component of high-power, short-pulse lasers. The maximum output of high-power pulsed lasers is always determined by laser resistance of gratings and this resistance is strongly dependent on the local near electric field intensity in the grating structure. We presented a novel method of reducing electric-field-enhancement in metal-dielectric grating by designing asymmetric grating ridge while maintaining high diffraction performance. Compared with the common isosceles trapezoidal grating, the grating with asymmetric ridge got a 0.04% reduction of diffraction efficiency in TE polarization at 1053 nm incident wavelength but a 21.3% reduction of maximal electric-field-enhancement in grating structure. This method can be applied to any surface-relief gratings to reduce the electric-field-enhancement for improving the laser induced damage threshold (LIDT) of grating and supporting the grating-based chirped pulse amplification (CPA) system to develop into higher peak-power levels.

摘要

衍射光栅是高功率、短脉冲激光器的重要光学元件。高功率脉冲激光器的最大输出总是由光栅的激光抗性决定，而这种抗性强烈依赖于光栅结构中的局部近电场强度。我们提出了一种新颖的方法，通过设计不对称光栅脊来降低金属 - 介质光栅中的电场增强，同时保持高衍射性能。与普通等腰梯形光栅相比，具有不对称脊的光栅在1053 nm入射波长下的TE偏振中衍射效率降低了0.04%，但在光栅结构中的最大电场增强降低了21.3%。该方法可应用于任何表面浮雕光栅，以降低电场增强，从而提高光栅的激光诱导损伤阈值（LIDT），并支持基于光栅的啁啾脉冲放大（CPA）系统发展到更高的峰值功率水平。